Three dimensional building element

ABSTRACT

Disclosed is a three dimensional building element having outer shells formed from cementitious compositions having different densities. The outer shell forming the exterior portion of the building element has a density greater than the interior shell to provide structure strength. The interior shell is formed from a lower density cementitious compound to provide an interior wall portion of a structure with a smooth finished appearance. The lower density of the interior cementitious compound enables the interior shell to obtain a smooth finished appearance without the need to apply various secondary coatings such as plaster or drywall.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 60/917,648 filed May 12, 2007, the contents of which are herebyincorporated in their entirety.

TECHNICAL FIELD

The present system relates to a three dimensional building element andto a method of forming the same and in greater detail the systemincludes a three dimensional building element having outer cementitiousshells having different densities such that the interior outer shell hasa lower density than the exterior outer shell of the building element.

BACKGROUND

Structures or buildings have commonly been formed from variousprefabricated elements. For example, one common prefabricated buildingelement comprises a three dimensional building elements havingcementitious shells to form portions or all of a completed structure.Such building elements have the advantage of being both structurallyvery sound and resistant to both moisture and fire.

An example of such a building element is one formed from athree-dimensional grid having an insulating body housed within the grid.The insulating body both lightens the building element while providinginsulation against both sound and the elements. The building element isfurther finished with an application of concrete commonly referred to asshotcrete on both sides of the element to provide structural support.

One specific example of a three dimensional building element commonlyused in assembling a structure includes a panel having two parallelwelded wire grid mats and associated web wires holding the wire gridmats at a distance from one another. An insulating body is arrangedbetween the wire grid mats. The web wires extend through and support theinsulating body between the wire grid mats. To improve the adhesion ofthe concrete to the insulating body, the insulating body may includeroughened surfaces. The resulting panels are finished with anapplication of shotcrete to both sides and can be used as structuralelements.

A further example, includes a three dimensional building element havingtwo wire mesh mats interconnected by web wires enclosing an insulatingbody with concrete applied to each side of the panel using the shotcreteprocess. The concrete shells are then interconnected by holes formed inthe insulating body which fills with concrete and interconnecting thetwo shells.

However, none of the above described systems of forming a structure frompreformed three dimensional building elements can do so efficiently andquickly since each requires various degrees of finishing andmodifications at the job site. In particular, the shotcrete formulationis applied to both sides of the panel or to both the interior wall andthe exterior wall portions of the element forming the structure.

A structure's interior walls have very different requirements than theexterior walls. For example, interior walls are often required to besmooth and to easily accept nails for hanging items. Exterior walls aretypically rough, such as in stucco finishes and are required to bedurable to withstand the elements. The interior walls of the structureformed using shotcrete require a separate step often involving anapplication of second or third cementitious or plaster compound toproduce a smooth soft finish. This extra step in finishing the interiorwalls requires both time and money.

Accordingly, it would advantageous to provide a method and system thatcould efficiently and quickly improve the construction process in theformation of a structure using a three dimensional building element.Furthermore, it would be advantageous if the steps of forming andfinishing the interior wall portion could be reduced to save both timeand money during the construction process.

SUMMARY

The present system includes a three dimensional building element and amethod of forming a three dimensional building element wherein thedensities of the outer cementitious shells differ. In particular, theouter shell forming the exterior portion of the building element has adensity greater than the interior shell to provide in part structuralstrength. The interior shell is formed from a lower density cementitiouscompound to provide an interior wall portion of a structure with asmooth finished appearance. The lower density cementitious compoundenables the interior shell to obtain a smooth finished appearancewithout the need to apply various secondary coatings such as plaster ordrywall.

In greater detail, the three dimensional building element includes twoparallel welded wire mesh mats with individual web wires joined at eachend to the mats for keeping the mats at a predetermined distance fromeach other. The individual web wires are arranged in rows connecting thetwo wire mesh mats. An insulating body spanning more than two of therows of web wires is positioned between the two wire mesh mats at apredetermined distance. The insulating body is further pierced by theweb wires.

The exterior cementitious outer shell of the building element is incommunication with (or encases) one of the two wire mesh mats.Additionally, the interior cementitious outer shell in communicationwith (or encases) the other of the two wire mesh mats. The exteriorcementitious outer shell has a density greater than the density of theinterior cementitious outer shell.

In one embodiment, the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.1 to 1, in a further embodiment the ration is greaterthan 1.2 to 1 and an additional embodiment includes a ratio greater than1.5 to 1. Example densities of the exterior cementitious outer shellinclude those between about 100 pcf to about 145 pcf and exampledensities of the interior cementitious outer shell include those betweenabout 55 pcf to about 110 pcf.

A further embodiment of the present system includes the ratio of thecompressive strength of the exterior cementitious outer shell to thecompressive strength of the interior cementitious outer shell beinggreater than 1.1 to 1, in a further embodiment the ration is greaterthan 1.2 to 1 and an additional embodiment includes a ratio greater than1.5 to 1. Example compressive strengths of the exterior cementitiousouter shell include those between about 2,500 psi to about 8,800 psi.and example compressive strengths of the interior cementitious outershell includes those between about 2,000 psi to about 5000 psi.

In an additional embodiment the interior cementitious outer shellincludes a foam admixture which reduces the density of the shell.Furthermore the fire resistance and moisture resistance of the interiorcementitious outer shell may be increased by the addition of fly ash.

A further embodiment of the three dimensional building element includesthe combination of the ratios of densities of the respective exteriorand interior outer shells and their respective density values. Thus, inthis embodiment the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.2 to 1 and the density of the exterior cementitious outershell is between about 100 pcf to about 150 pcf and the density of theinterior cementitious outer shell is between about 50 pcf to about 110pcf.

In an additional embodiment, the three dimensional building elementincludes the combination of both the density ratios and compressivestrength ratios of the respective outer cementitious shells. Thus, inthis embodiment the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.2 to 1 and the ratio of the compressive strength of theexterior cementitious outer shell to the compressive strength of theinterior cementitious outer shell is greater than 1.2 to 1. In addition,the embodiment includes the interior cementitious outer shell includinga foam admixture.

The system also includes a method of forming a three dimensionalbuilding element. The method includes the steps of providing twoparallel welded wire mesh mats with individual web wires joined at eachend to the mats for keeping the mats at a predetermined distance fromeach other. The individual web wires are arranged in rows connecting thetwo wire mesh mats. The method further includes piercing an insulatingbody positioned between the wire mesh mats by the web wires. Furtherincluded in the method is the application of a cementitious compositionto one of the two wire mesh mats to form an exterior outer shell and theapplication of a second cementitious composition to the other of the twowire mesh mates to form an interior outer shell. The ratio of the firstand second cementitious composition is greater than 1.1 to 1.

The method may also include in a further embodiment the application tothe interior cementitious outer shell a composition comprising a drywallpowder and primer based paint. The applied composition comprising adrywall powder and primer based paint may be sanded to a level wallfinish of between about 4 to about 5 according to ASTM C 840 standard.

DRAWINGS

In the drawings:

FIG. 1 is an axonometric view of a three dimensional building elementaccording to the invention;

FIG. 2 is a plan view of the three dimensional building of the presentsystem and method as shown in FIG. 1; and

FIG. 3 is an interior cross sectional view of a three dimensional panelcomprising a three-dimensional grid body having an insulating foamedbody formed within, and further including the exterior outercementitious shell and the interior cementitious outer shell andinterior cementitious outer shell.

DETAILED DESCRIPTION

Disclosed is a three dimensional building element and method of forminga three dimensional building element wherein the densities of the outercementitious shells differ. In particular, the interior outer shell orthat shell forming an interior wall portion of a structure has a densityless than the density of the exterior shell forming the exterior portionof the structure. The reduced density of the cementitious interior shellenables the shell to obtain a smooth finished appearance without theneed to apply various secondary coatings such as plaster or drywall.

The outer shells of the three dimensional building element are formedfrom a cementitious composition. The cementitious composition may bevaried such that the densities of the shells may differ wherein theexterior shell has a density greater than the interior shell. Thecementitious composition may be applied to the three dimensionalbuilding element by using several techniques including dry or wetcementitious applications to a prescribed thickness.

As an alternative to the shotcrete process the cementitious compositionmay be applied to the building element using a small batch process. Thesmall batch process may include the use of a foam generator such as thatavailable from Goodson & Associates of Wheat Ridge, CO and known as theGoodcell Foam Generator, for producing a foamed cementitiouscomposition. By using a small batch process the cementitious compositioncan be applied to the building element using relatively unskilled laborsaving the expense of using a skilled shotcrete operator. Furthermore,individual mixes for various wall portions of the structure can beeasily mixed for the structural load of the building element or type offinish desired. Additionally, only portions of the structure can beworked on at a time.

The strength of the cementitious composition can vary based uponapplication and load factors. Furthermore the cementitious compositionmay be varied based upon other performance criteria. However, thedensity of the formed interior cementitious outer shell is always lessthan the density of the formed exterior cementitious outer shell of thethree dimensional building element.

The present system may use several mix variations from the formulas setforth for different purposes within a specific building project. Forexample, an interior, non-load bearing walls may receive a lowerstrength concrete application.

The exterior cementitious outer shell may be comprised of a concrete mixwith multiple admixtures. Admixtures maybe added to reduce waterintrusion through the finished panel; improve compressive and tensilestrength of the concrete; and reduce cracking related to moisture loss,commonly referred to as shrinkage cracking. The compressive strength ofthe mix may vary between 2500 psi and 8,000 psi, and the density of themix may be varied between 100 pcf and 145 pcf based on the requirementsof a specific application. Such concretes are ideal for exteriorfinishes and walls requiring higher-strength, including shear walls.

The interior cementitious outer shell may be comprised of a concrete mixwith multiple admixtures. The purpose of the admixtures in the interiorcementitious outer shell is to in part to lower the density of theconcrete, while maintaining required strength. Lowered concrete densityresults in lighter wall and floor and roof systems. In addition, a moreaesthetically pleasing interior finish is achieved allowing for smoothwalls, pictures to be hung and wood trim to be installed. Thecompressive strength of the mix may vary between 2000 psi and 5,000 psi,and the density of the mix may be varied between 55 pcf and 110 pcfbased on the requirements of a specific application. Such concretes areideal for interior finishes.

By way of example, and not limitation, the mix components of caninclude:

Exterior Mix forming the Exterior Cementitious Outer Shell

-   -   800 lb—Portland Cement (type 1)    -   2240 lb—Sand    -   30 gal—Water    -   15 lb—Kalmatron Additive KC-A

Interior Mix forming the Interior Cementitious Outer Shell

-   -   800 lb—Portland Cement (type 1)    -   2240 lb—Sand    -   28 gal—Water    -   10 ft³—Foam admixture such as that available from Goodson &        Associates of Wheat Ridge, CO and known as GoodCell Foam        Additive made using Goodcell Type A-100 chemical

Furthermore, the three dimensional building element may include anelastomeric coating to aid in securring the foam and the mesh duringtransit. Additionally, the elastomeric coating may assist in securingany mechanical/electrical/plumbing material after the material has beeninstalled in the dimensional building element and to work as a bondingagent to adhere the concrete to the panel system.

An additional embodiment of the present system includes a furtherfinishing process to achieve an even more finished flat and levelinterior wall finish to a degree of about a 4 to 5 finish according toASTM C840 standard. The interior finish is applied after the curing ofthe interior cementitious composition. The interior finishing materialis comprised of drywall powder and a primer based paint. The drywallpowder is mixed into the primer based paint and then sprayed or rolledonto the interior surface. After the primer and powder mix has cured,the interior surface is sanded smooth to the desired finish.

A further embodiment for non-load bearing exterior walls includes usingonly an exterior cementitious outer shell with a gypsum sheathingapplied to the interior side of the wall. To satisfy code wind loadsprovisions in high wind areas, portions of the insulating foam may beremoved to allow structural concrete ribs to be added to the systemduring cementitious coating application.

Referring now in greater detail to the drawings in which like numeralsindicate like items throughout the several views, FIGS. 1-3 depict thepresent three dimensional building element and method of forming a threedimensional building element, in the various embodiments of the presentinvention.

The three dimensional building element as shown in FIGS. 1-3 is formedof outer and inner wire mesh mats 1 and 2 respectively, which arearranged parallel to and at a predetermined distance from each other.Each wire mesh mat 1 or 2 has several longitudinal wires 3 or 4 andseveral cross wires 5 or 6 which cross each other and are weldedtogether at the points of intersection. The distance between thelongitudinal wires 3, 4 and between the cross wires 5, 6 is selectedaccording to the static requirements of the structural member, and forexample is within the range of 50 to 150 mm. The distances can be equal,or different.

The diameters of the longitudinal and cross wires 3, 4 or 5, 6 are alsoselectable according to the static requirements and are preferablywithin the range from 2 to 6 mm. The surface of the wire mesh mats 3, 4,5, 6 can be, within the scope of the invention smooth or ribbed.

The two wire mesh mats 1, 2 are joined together by several web wires 7,7′ into a dimensionally stable mesh body. The web wires 7 are welded attheir respective ends to the wires of the two wire mesh mats 1, 2,wherein, within the scope of the invention, the web wires 7 are weldedeither, to the respective longitudinal wires 3, 4 or to the cross wires5, 6. The web wires 7 are arranged obliquely alternately in oppositedirections, or. like a trellis as a result of which the mesh body isreinforced against shear stress.

An insulating body 8 is arranged in the gap between the wire mesh mats1, 2, at a predetermined distance from the wire mesh mats. Theinsulating body 8 has top and bottom, or outside and inside surfaces 9which run parallel to the wire mesh mats 1, 2. The insulating body 8serves for heat and sound insulation and for example is made of foamplastics such as polystyrene or polyurethane foam.

The thickness of the insulating body 8 is freely selectable and is, forexample, within the range from 20 to 200 mm. The distances from theinsulating body 8 to the wire mesh mats 1, 2 are also freely selectableand are, for example, within the range from 10 to 30 mm. The structuralmember can be made in any length and width. On the basis of the methodof production, a minimum length of 100 cm and standard widths of 60 cm,100 cm, 110 cm, 120 cm have proved to be advantageous.

The exterior cementitious outer shell 14 of the building element is incommunication with (or encases) one 2 mat of the two wire mesh mats 1,2. As shown in FIG. 3 the exterior cementitious outer shell 14 encasesthe entire wire mesh mat 2 and protrudes beyond the mat 2. The thicknessof either the interior 13 or exterior 14 cementitious outer shell canvary depending upon the desired strength for the building element andthe application of the element. Furthermore, as shown in FIG. 3, theinterior cementitious outer shell 13 is in communication with (orencases) the other 1 mat of the two wire mesh mats 1, 2. The thicknessesof the interior cementitious outer shell 13 and the exteriorcementitious outer shell 14 can be different or the same. The exteriorcementitious outer shell 14 has a density greater than the density ofthe interior cementitious outer shell 13. Furthermore, the mixformulations of the cementitious composition comprising the exteriorcementitious outer shell 14 can be different form the interiorcementitious outer shell 13.

In one embodiment, the ratio of the density of the exterior cementitiousouter shell 14 to the density of the interior cementitious outer shell13 is greater than 1.1 to 1, in a further embodiment the ration isgreater than 1.2 to 1, a further embodiment includes a ratio greaterthan 1.3 to 1 and an additional embodiment includes a ratio greater than1.5 to 1.

By way of example and not limitation, the densities of the exteriorcementitious outer shell 14 include those between about 100 pcf to about145 pcf. Example densities of the interior cementitious outer shell 13include those between about 55 pcf to about 110 pcf. Further examplesinclude the densities of the exterior cementitious outer shell 14include between about 100 pcf to about 150 pcf. and example densities ofthe interior cementitious outer shell 13 include those between about 50pcf to about 120

A further embodiment of the present system includes the ratio of thecompressive strength of the exterior cementitious outer shell 14 to thecompressive strength of the interior cementitious outer shell 13 beinggreater than 1.1 to 1, in a further embodiment the ration is greaterthan 1.2 to 1 and in an additional embodiment the ratio is greater than1.5 to 1. Example compressive strengths of the exterior cementitiousouter shell 14 include those between about 2,500 psi to about 8,800 psi.and example compressive strengths of the interior cementitious outershell 13 includes those between about 2,000 psi to about 5000 psi.

While applicants have set forth embodiments as illustrated and describedabove, it is recognized that variations may be made with respect todisclosed embodiments. Therefore, while the invention has been disclosedin various forms only, it will be obvious to those skilled in the artthat many additions, deletions and modifications can be made withoutdeparting from the spirit and scope of this invention, and no unduelimits should be imposed except as set forth in the following claims.

1. A three dimensional building element comprising: two parallel weldedwire mesh mats and individual web wires joined at each end to the matsfor keeping the mats at a predetermined distance from each other, theindividual web wires being arranged in rows connecting the two wire meshmats; an insulating body spanning more than two of the rows of web wiresand defining two opposite surfaces arranged parallel to and positionedbetween the wire mesh mats and at a predetermined distance therefrom,the insulating body being pierced by the web wires; and an exteriorcementitious outer shell in communication with one of the two wire meshmats and an interior cementitious outer shell in communication with theother of the two wire mesh mats, wherein the exterior cementitious outershell has a density greater than the density of the an interiorcementitious outer shell.
 2. The three dimensional building element ofclaim 1, wherein the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.1 to
 1. 3. The three dimensional building element ofclaim 1, wherein the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.5 to
 1. 4. The three dimensional building element ofclaim 1, wherein the density of the exterior cementitious outer shell isbetween about 100 pcf to about 145 pcf.
 5. The three dimensionalbuilding element of claim 1, wherein the density of the interiorcementitious outer shell is between about 55 pcf to about 110 pcf. 6.The three dimensional building element of claim 1, wherein thecompressive strength of the exterior cementitious outer shell is betweenabout 2,500 psi to about 8,800 psi.
 7. The three dimensional buildingelement of claim 1, wherein the compressive strength of the interiorcementitious outer shell is between about 2,000 psi to about 5000 psi.8. The three dimensional building element of claim 1, wherein theinterior cementitious outer shell includes a foam admixture.
 9. Thethree dimensional building element of claim 8, wherein the interiorcementitious outer shell further includes fly ash.
 10. A threedimensional building element comprising: two parallel welded wire meshmats and individual web wires joined at each end to the mats for keepingthe mats at a predetermined distance from each other, the individual webwires being arranged in rows connecting the two wire mesh mats; aninsulating body spanning more than two of the rows of web wires anddefining two opposite surfaces arranged parallel to and positionedbetween the wire mesh mats and at a predetermined distance therefrom,the insulating body being pierced by the web wires; an exteriorcementitious outer shell in communication with one of the two wire meshmats and an interior cementitious outer shell in communication with theother of the two wire mesh mats, wherein the exterior cementitious outershell has a density greater than the density of the an interiorcementitious outer shell; and wherein the ratio of the density of theexterior cementitious outer shell to the density of the interiorcementitious outer shell is greater than 1.2 to 1 and wherein thedensity of the exterior cementitious outer shell is between about 100pcf to about 150 pcf and the density of the interior cementitious outershell is between about 50 pcf to about 110 pcf.
 11. The threedimensional building element of claim 10, wherein the compressivestrength of the exterior cementitious outer shell is between about 2,500psi to about 8,800 psi.
 12. The three dimensional building element ofclaim 10, wherein the compressive strength of the interior cementitiousouter shell is between about 2,000 psi to about 5000 psi.
 13. The threedimensional building element of claim 10, wherein the interiorcementitious outer shell includes a foam admixture.
 14. The threedimensional building element of claim 13, wherein the interiorcementitious outer shell further includes fly ash.
 15. A threedimensional building element comprising: two parallel welded wire meshmats and individual web wires joined at each end to the mats for keepingthe mats at a predetermined distance from each other, the individual webwires being arranged in rows connecting the two wire mesh mats; aninsulating body spanning more than two of the rows of web wires anddefining two opposite surfaces arranged parallel to and positionedbetween the wire mesh mats and at a predetermined distance therefrom,the insulating body being pierced by the web wires; an exteriorcementitious outer shell in communication with one of the two wire meshmats and an interior cementitious outer shell in communication with theother of the two wire mesh mats, wherein the exterior cementitious outershell has a density greater than the density of the an interiorcementitious outer shell; wherein the ratio of the density of theexterior cementitious outer shell to the density of the interiorcementitious outer shell is greater than 1.2 to 1 and wherein the ratioof the compressive strength of the exterior cementitious outer shell tothe compressive strength of the interior cementitious outer shell isgreater than 1.2 to 1; and wherein the interior cementitious outer shellincludes a foam admixture.
 16. The three dimensional building element ofclaim 15, wherein the interior cementitious outer shell further includesfly ash.
 17. The three dimensional building element of claim 15, whereinthe compressive strength of the exterior cementitious outer shell isbetween about 2,500 psi to about 8,800 psi.
 17. The three dimensionalbuilding element of claim 15, wherein the compressive strength of theinterior cementitious outer shell is between about 2,000 psi to about5000 psi.
 18. A method of forming a three dimensional building elementcomprising the steps of: providing two parallel welded wire mesh matsand individual web wires joined at each end to the mats for keeping themats at a predetermined distance from each other, the individual webwires being arranged in rows connecting the two wire mesh mats;providing an insulating body spanning more than two of the rows of webwires and defining two opposite surfaces arranged parallel to andpositioned between the wire mesh mats and at a predetermined distancetherefrom, the insulating body being pierced by the web wires; applyinga first cementitious composition to one of the two wire mesh mats toform an exterior outer shell; applying a second cementitious compositionto the other of the two wire mesh mats to form an interior outer shell;and wherein the ratio of the density of the first cementitiouscomposition applied to the exterior cementitious outer shell to thedensity of second cementitious composition applied to the interiorcementitious outer shell is greater than 1.1 to
 1. 19. The method ofclaim 18, wherein the ratio of the density of the exterior cementitiousouter shell to the density of the interior cementitious outer shell isgreater than 1.2 to 1 and wherein the ratio of the compressive strengthof the exterior cementitious outer shell to the compressive strength ofthe interior cementitious outer shell is greater than 1.2 to
 1. 20. Themethod of claim 18, wherein the applied cementitious composition appliedto the other of the two wire mesh mates to form an interior outer shellincludes a foam admixture.
 21. The method of claim 20, wherein theapplied cementitious composition applied to the other of the two wiremesh mates to form an interior outer shell includes fly ash.
 22. Themethod of claim 19, further includes applying to the interiorcementitious outer shell a composition comprising a drywall powder andprimer based paint.
 22. The method of claim 22, further includingsanding the applied composition comprising a drywall powder and primerbased paint to a level wall finish of between about 4 to about 5 of ASTMC 840 standard.